Control of hypertension as defined traditionally, is known to reduce recurrent stroke risk in whites, but may not in African-Americans and Latinos. African-Americans and Latinos may be more sensitive to a given level of hypertension than whites. Alternatively, traditional measures of blood pressure control may be suboptimal in a subgroup of hypertensives with little or no nocturnal decline in their blood pressure ("non-dippers"), and African-Americans are more likely to be non-dippers. Other factors to consider are those unrelated to hypertension control such as noncompliance with specific stroke prevention regimens or lack of availability of adequate medical care. Additionally, a recently described polymorphism of the ACE gene has been associated with an increased risk of cardiovascular and, especially in African- Americans, cerebrovascular disease. This genetic predisposition may operate by increasing susceptibility to hypertensive vascular damage. In preliminary studies, the candidate has demonstrated that African- Americans and Latinos have a risk of stroke recurrence twice that of white, non-Latinos during the first 2 years post-stroke. The long range goal of the MCSDA proposal is to better understand which mechanism contributes most significantly to the observed increased stroke recurrence rate in minority populations. This is to be accomplished in three phases. In the first, a case-control study will be conducted to determine the stroke risk conferred by a lack of nocturnal decrease in blood pressure and/or a polymorphism in the gene coding for angiotensin converting enzyme. In the second, a longitudinal study will determine the significance of the effect of these factors and of post-stroke control of hypertension on the risk of stroke recurrence. Finally, a pilot study will be conducted to determine if rigorous control of hypertension in conjunction with measures to ensure compliance will decrease recurrent stroke. Under the sponsorship of Dr. Stanley Tuhrim, the candidate will also pursue further training in neuroepidemiology and biostatistics, have an active role in the clinical care and investigation of patients with cerebrovascular disease and will have defined teaching duties. This will enable the candidate to develop an independent program of clinical investigation that will complement existing research programs at the Mount Sinai School of Medicine.